Commuter truck

[Clydesdale]

Could a guy put together a Bronco bodied, or 60's era Domestic half ton step side shorty box on a half ton 4x4 chassis, 3.54 geared, running say 33/9.5's which gives a net gearing of 2.80... and get 20+ out of 6.9? or a 7.3/ZF?

Maybe even 25? I know a 6.2 in a 2wd with the A-833 trans (that would be pimp=had one in a 6 cyl Bronc) can get 28 ish... talked to a .75ton 6.2 700r4 suburban the other day, and they got 26 ish towing a trailer.... at 55 but never the less.

I get 15 out of my 5.0/AOD 3.54 geared 33/9.5 Bronco.. and it could probably use a tune.

I have the chassis, there are dead Bronc's everywhere, also an IH 1963 (?) step side 2x, found an IDI ZF 2wd...

Applying for a job that will create 600 miles of driving a week... be nice to have a long legged oil burner that netted me 20+... be awesome if it were 4x4.

My Bronco is veeeeeeeeeeeeeeeeerrrrrrrrrry relaxing to drive, everything is adding together to make this make sense.

 

[LCAM-01XA]

Well, I consistently get 20-21 with my big dually with an E4OD, so in a smaller and lighter truck with a bolt-action trans and proper gearing I see no problem of achieving 25mpg cruising down the interstate. Heck, don't Mathias (Mel's son) get about that in his halfton flareside with a 6.9 and a ZF-5?

 

[The Warden]

It's certainly a thought, but I tend to think that you aren't going to get very good economy with 33" tires, partially due to the tires being wider (and therefore more rolling resistance) and partially due to the truck being taller (and therefore less aerodynamic). IMHO you'd be better off with a 3.07 rear end and stock height (ideally the stock height for a 2 wheel drive). For a freeway cruiser, aerodynamics plays a big role. The less air your truck has to move out of the way, the less the engine has to work to keep you at a given speed. The taller and wider your truck is, the more air it's needing to push out of the way to continue moving forward.

Tonka Doc had a dualie with a 3.07 rear end and a ZF5 a few years back; IIRC he was getting low to mid 20's consistently. You might do a search for some of his earlier posts, or maybe he'll respond on here.

I'm curious to see what you end up with...

 

[LCAM-01XA]

The 33" tires he's thinking of are 9.5" wide tho, which in reality makes them barely wider than the factory sized tires.

 

[The Warden]

Thanks, I missed that....although, with that said, I thought I had heard before that taller tires can still have a negative effect on fuel economy even if they're the same width? There's also the aerodynamic factor to consider...

 

[LCAM-01XA]

Yeah, more rotating mass in larger tires, tho it his case the difference would be negligible, methinks.

 

[subway]

i think the nightmoose (6.9 in a F150 flairside NA with a ZF) was getting 26 on the trip. i believe that is the number he mentioned. his is also 2wd with stock size tires though.

above 50 mph your aerodynamics are the primary make or brake for fuel miliage though.

 

[Shadetreemechanic]

Thanks, I missed that....although, with that said, I thought I had heard before that taller tires can still have a negative effect on fuel economy even if they're the same width? There's also the aerodynamic factor to consider...

I read an article that stated that a taller tire would give less rolling resistance than a smaller tire of the same width. It was saying that the deflection on the tire was less and therefore gave less rolling resistance. I used that to justify the 33's I put on my truck.
My mileage is down since upsizing tires.

 

[Clydesdale]

Well, One needs to see if one gets the job first, if the Bronc i doing 15 ~ and I tune it to even 17... will take almost a year to recuperat the cost of the project truck .

Ruff math 15 mpg/600 miles = 40 gallons x 2.75.. +110 a week, 20/600 30 gallons x 2.75 = 82.50 25/600 24 gallons x 2.75 = 54 a week. so if i have exactly 2k in it... I could have driven the Bronc for a ear and been money = money. Shooting for $1,000...

Used detroit/IDI, pushing for an A-833... 2.75- 3.08 rear gears (in O/D that gives me 2.00 ish final drive) and something little to drop it all in, 4x4 is a huge bonus, as It gets UGGGGGGGLY on this commute in the winter, but a small lightweight Ford/Chevy/IH 2wd short box stepside would be ideal, then that is contingent upon how day care works out, if Mama doesn't change shifts, and I end up ferrying the kids, then a Bronc makes the most sense.

Which limits me to 3.54's for longest gearing options, and looking at the 33/9.50's to leg it out bit.


But I could still find the A-833 trans.... My 6 cyl Bronc had one, and know of another 6 cyl Bronc that is rumored to have one. a 25 mpg Bronc would be pimp.

Ford seemed to think in 1983 (read the fine print its funny) that their 6 cyl Bronc could do 27....

You must be registered for see images attach

 

[The Warden]

What is the A-833 tranny? Will it handle the torque output of an IDI?